6-1 Converting Rates

Warm-up Thursday, October 22, 2009 Write each ratio as a fraction in simplest form. a)36 to 48 b)60 to 24 c)16 : 12 d)15 : 27

Rates and Conversions Section 6.1 Objective: We will be able to express rates with different units.

Changing Units Change 27 feet per second to inches per second. Start by writing the rate as a division

1 ftin 324 in 27 ft 12 ⋅ = 1 sec 1 sec 11ftft

Second we multiply by fancy Next change units as needed to “ones”. Thisfinish mightthe change the multiplication and get look of the problem, butunits not its the correct value. Finally, we multiply to get our answer.

Another Example (not animated) A pool fills at 12 quarts per minute.

Find out how many gallons per hour the pool fills.

Before You Try! Please copy down (and use!!!) these

helpful English conversions: 1 mile = 5280 feet 1 cup = 8 fluid ounces 1 pint = 2 cups 1 quart = 2 pints 1 gallon = 4 quarts 1 pound = 16 ounces

Now You Try! Change $7.10 per hour to dollars

per minute.

Change 65 miles per hour to feet

per second.

Try some more! Convert 52 inches per minute to

yards per hour.

Change 36 miles per year to inches

per hour.

Some thoughts about why. Why would we possibly bother with this? At the 2008 Olympics Usain Bolt ran the

100 meter dash in 9.69 sec. How fast is that? (We change rates to gain meaning) If one job pays a yearly salary of $45,000

and another pays $20 an hour, which pays more assuming 40-hour work weeks? (We change rates to solve problems)

Homework Time! With lots of time to work on it, here

is your homework!!! Page 294 (2007 book): 17-22; 27-29

Ticket to Leave 1. A jet flies 540 miles per hour. Write its

rate in miles per minute. 2. A car is traveling at 60 miles per hour.

Write its rate in feet per second. 3. An insect crawls 1 foot in 10 seconds.

At this rate, how far will it crawl in 5 minutes?